This year’s report focused on the need for women to have the right to make choices about their reproductive health and the importance of ensuring timely access to family planning materials for reduced fertility rate.

China was the most populous country in the world with a population exceeding 1.4 billion, while in Africa, Nigeria topped, having risen to 201 million people. The West African country is set for one of the biggest population booms in world history and is expected to reach nearly 1 billion people by 2100.

Africa, with more than 1.2 billion people, is the second-largest and second most populous continent on earth, and this has been blamed largely on the very high fertility rates and the little family planning in most regions.

In spite of the global gains in securing sexual and reproductive rights over the past 50 years, many population groups are still left behind, this year’s SWOP report released by the United Nations Population Fund said.

It said that global fertility rates have roughly halved since the agency began operations in 1969. But it also highlights how reproductive rights remain inaccessible to many, including more than 200 million women worldwide who want to prevent a pregnancy but don’t have access to contraceptives.

“The lack of this power – which influences so many other facets of life, from education to income to safety – leaves women unable to shape their own futures,” said UNFPA Executive Director Natalia Kanem.

By 2100, more than half of the world’s growth is expected to come from Africa, experts say, as the continent experiences exponential growth in life expectancy apart from its relatively young population.

While it’s a good thing to have a higher life expectancy in Africa, there are concerns that the continent might become overcrowded. Analysts argue that prolonged lifespan will cause economic inactivity by older workers, which will ultimately lead to an economic disaster across Africa.

Despite these concerns, the following African countries are increasing at an advanced rate: